With 2017 in full swing and the launch of the Galaxy S8 mere months away, Samsung hopes to put to rest the case of the flaming Note 7 and the subsequent recall of what many considered to be the best smartphone ever built.

Today at a press conference in Korea, the tech giant announced the results of its own internal investigation and that of three other independent firms.

A lot of tech jargon was thrown around to explain what happened, but simply put, battery issues were discovered to be the root cause of the problem.

Here’s everything you need know about the Note 7 issue.

What happened?

Last August, shortly after the Galaxy Note 7 went on sale, multiple users reported of phones bursting into flames.

Samsung was relatively quick to respond, halting the sale of the Note 7 and announcing a replacement program.

Its initial investigation found that batteries from one of its two suppliers were faulty. To meet the demand for the Note 7 it ramped up the production of batteries from its other supplier. Recalled Note 7s were replaced and Samsung began selling the phones with the new battery.    

More cases of exploding phones with the new batteries were reported.

Samsung pulled the plug on the Note 7 completely and issued a global recall.

As of today 96% of the 3 million Note 7s sold worldwide have been returned to Samsung.

Who did the testing?

700 researchers from inside Samsung tested 200,000 Note 7 smartphones and over 30,000 batteries.

Samsung also enlisted the services of three independent firms (UL, Exponent, and TÜV Rheinland) to conduct their own tests. Representatives from all 3 firms were also at the event to announce their findings.

What did the investigation find?

After months of tests, investigators didn’t find anything wrong with the Note 7 itself.

Instead all tests pointed to problems in the design and manufacturing of the batteries.

The batteries were manufactured by two different companies using designs and specifications from Samsung.

Two distinct battery issues from both companies were identified.

The batteries from company A had “an electrode deflection, an incorrect positioning of the negative electrode tip in the upper right corner of the battery.”

While the batteries from company B had “an abnormal weld spot (that) led to an internal short circuit.”

Were the Note 7’s other features a factor?

No. Tests found that the fast charging feature on the Note 7 had nothing to do with the problem. Neither did other new features added to the Note 7 including the iris scanner, water resistance and USB-C connectivity.

Samsung also says that contrary to speculation, there was adequate space inside the phone for the battery to swell and contract during charging. In fact, the company claims the Note 7 could have accommodated an even higher capacity battery.

Was the release of the Note 7 rushed? And was this a factor?

Samsung says the Note 7 was released in accordance with its annual roadmap. While Samsung has made a habit of announcing its Galaxy Note smartphone every September, the Note 7’s predecessor the Note 5 was also unveiled in August.

Samsung believes however that rushing its other battery supplier may have triggered the manufacturing issue discovered in Battery B.

So whose fault is it?

Samsung takes full responsibility for the incident. Not only were battery design and specifications from them, they also take the blame for failing to discover the issue which could have been avoided with more rigorous testing.

What is being done so this won’t happen again?

Samsung executives tell us they will continue to strive for an open corporate culture.

Following the results of their investigation Samsung has formed an independent Battery Advisory Council composed of academics from Berkeley, Cambridge and Stanford.

More importantly they have adapted a new 8-point checklist for testing new products. This includes what it calls an enhancement to existing processes like x-ray scans.

And new tests including ones that simulate a variety of use case scenarios.

Did Samsung push too hard? Will it stop innovating?

Samsung did push hard, but we expect nothing less from the world’s top tech brands. To truly innovate tech companies need to continuously push the boundaries of what’s possible. But the harder the push, the greater the need for more stringent quality assurance testing processes.

Samsung says it is committed to “innovation that redefines what’s possible in safety,” their way of saying they will continue to innovate but will be more involved and careful next time.